Ye Yong, Xing Haiting, Li Yue
Department of Pharmaceutical Engineering, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, People's Republic of China.
Int J Nanomedicine. 2014 Sep 19;9:4475-84. doi: 10.2147/IJN.S64313. eCollection 2014.
Sasanquasaponin, a bioactive compound isolated from seeds of Camellia oleifera, shows central effects in our previous research. In order to investigate its neuroprotective effects, a new kind of nanocapsule with photo responsiveness was designed to deliver sasanquasaponin into the brain and adjusted by red light. The nanocapsule was prepared using sasanquasaponin emulsified with soybean lecithin and cholesterol solution. The natural phaeophorbide from silkworm excrement as a photosensitizer was added in the lipid phase to make the nanocapsules photo responsive. The physicochemical properties of encapsulation efficiency, size distribution, morphology and stability were measured using high-performance liquid chromatography, particle size analyzer, transmission electron microscope, differential scanning calorimetry and thermogravimetry. Photo responsiveness was determined by the sasanquasaponin release in pH 7.5 phosphate buffer under the laser at 670 nm. The neuroprotective effects were evaluated by the expression of tyrosine hydroxylase (TH), decrease of inflammatory cytokines TNF-α and IL-1β in the brain, and amelioration of kainic acid-induced behavioral disorder in mice. The nanocapsules had higher encapsulation efficiency and stability when the phaeophorbide content was 2% of lecithin weight. The average size was 172.2 nm, distributed in the range of 142-220 nm. The phaeophorbide was scattered sufficiently in the outer lecithin layer of the nanocapsules and increased the drug release after irradiation. TH expression in brain tissues and locomotive activities in mice were reduced by kainic acid, but could be improved by the sasanquasaponin nanocapsules after tail vein injection with 15 minutes of irradiation at the nasal cavity. The sasanquasaponin took effect through inflammatory alleviation in central tissues. The sasanquasaponin nanocapsules with phaeophorbide have photo responsiveness and neuroprotective effects under the irradiation of red light. This preparation presents a new approach to brain neuroprotection, and has potential for clinical application.
油茶皂苷是从油茶种子中分离出的一种生物活性化合物，在我们之前的研究中显示出中枢作用。为了研究其神经保护作用，设计了一种具有光响应性的新型纳米胶囊，将油茶皂苷输送到大脑并通过红光进行调控。该纳米胶囊是用油茶皂苷与大豆卵磷脂和胆固醇溶液乳化制备而成。将来自蚕粪的天然脱镁叶绿酸作为光敏剂添加到脂质相中，使纳米胶囊具有光响应性。使用高效液相色谱、粒度分析仪、透射电子显微镜、差示扫描量热法和热重分析法测定了包封率、粒径分布、形态和稳定性等物理化学性质。通过在670 nm激光照射下，pH 7.5磷酸盐缓冲液中油茶皂苷的释放来确定光响应性。通过酪氨酸羟化酶（TH）的表达、大脑中炎性细胞因子TNF-α和IL-1β的减少以及对小鼠 kainic 酸诱导的行为障碍的改善来评估神经保护作用。当脱镁叶绿酸含量为卵磷脂重量的2%时，纳米胶囊具有较高的包封率和稳定性。平均粒径为172.2 nm，分布在142 - 220 nm范围内。脱镁叶绿酸充分分散在纳米胶囊的外层卵磷脂层中，并在照射后增加了药物释放。Kainic 酸降低了脑组织中TH的表达和小鼠的运动活性，但在尾静脉注射后鼻腔照射15分钟，油茶皂苷纳米胶囊可使其得到改善。油茶皂苷通过减轻中枢组织炎症发挥作用。含脱镁叶绿酸的油茶皂苷纳米胶囊在红光照射下具有光响应性和神经保护作用。这种制剂为脑保护提供了一种新方法，具有临床应用潜力。
